1. Field of Invention
The present invention relates to a start clutch device, and more particularly, to a start clutch device in which oil circulation paths are separated from each other and expanded inside a housing in order to realize lubricating and cooling performance while increasing the axial supporting force of components which are disposed inside the housing.
2. Description of Related Art
A torque converter is typically used as a start clutch device of a vehicle, in particular, as a start device of a vehicle having an automatic transmission (AT), a continuously variable transmission (CVT) or an automated manual transmission (AMT). The torque converter maintains a driving source in the rotating state by allowing relative rotation between an input shaft of a transmission and an engine output shaft via a fluid coupling in a stopped state of a vehicle.
Thus, at the start of a vehicle, the relative rotation between the engine output shaft and the input shaft of the automatic transmission is allowed and smooth and soft start performance is realized through the lubricating action of the fluid and the enhancement of torque. However, a power loss is caused by the slipping of the fluid, thereby lowering fuel efficiency.
Recently, as the number of stages of automatic transmissions is increasing, the output torque and power of an engine are increasing, and a small size of automatic transmissions is required, start clutch devices that do not use fluid have been proposed.
In the meantime, FIG. 1 shows a start clutch device of the related art which does not use a torque converter. This start clutch device was disclosed in Korean Patent Application Publication No. 10-2004-0020969, titled “START CLUTCH DEVICE.” That is, a clutch 10 including a friction material 14 and a piston 20 and a damper device 12 are disposed inside a housing 2. The housing 2 is connected to an engine, and is disposed such that it can rotate using rotational power supplied from the engine.
However, according to this approach, gaps a and b provided in the inner and outer radius directions of a sleeve shaft 41 are very narrow such that oil does not properly circulate inside the housing, which is problematic.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.